Electrical systems for road vehicles

ABSTRACT

In an electrical supply system for a road vehicle, a plurality of electrical loads have associated therewith a plurality of switches. The system has a plurality of feed lines and each switch when operated causes a unique combination of at least two of the feed lines to be energized. This combination of feed lines serves in turn to operate means which causes power to be supplied from a supply line to the appropriate load.

United States Patent Holt 1 51 Mar. 27, 1973 [54] ELECTRICAL SYSTEMS FOR ROAD [56] References Cited VEHICLES UNITED STATES PATENTS [75] Inventor: William David Holt, Colne, England 3,058,094 10/1962 Spingies et al ..307/1 15 X [73] Asslgnee' 9 Lucas (lndusmes) 3,466,505 9/1969 Anderson ..307 115 x Birmingham, England Filed: J y 15, 1971 Primary Examiner-Herman J. Hohauser [21] Appl. No.: 163,052 Attorney-Holman & Stern Related U.S. Application Data [57] ABSTRACT [63] Continuation of 1969' In an electrical supply system for a road vehicle, a pluabandoned rality of electrical loads have associated therewith a 52 U s.c1 ..307/l0R 307/38 307/115 plurality swimhes' The system has a plurality 51 1m.c1. ..1i02 3/00 feed lines and each Switch when mated a 5 unique combination of at least two of the feed lines to Field of Search ..307/9,10 R, 112, 113,115, 307/38, 39, 40,10 LS be energized. This combination of feed lines serves in turn to operate means which causes power to be supplied from a supply line to the appropriate load.

2 Claims, 1 Drawing Figure PATENTED MARE? I975 INVENTOE WILLIAM DAVID HOLT ATTORN EYS ELECTRICAL SYSTEMS FOR ROAD VEHICLES plurality of feed lines, each switch when operated, 1O

energizing a unique combination of at least two of the feed lines, and energization of said combination of feed lines serving to operate means which causes power to be supplied from the supply line to the appropriate load.

The accompanying drawing is a circuit diagram illustrating a simplified example of the invention.

Referring to the drawing, the vehicle includes a battery 11 which supplies power to a supply line 12 extending around the vehicle. The battery 11 also supplies power to a relay control line 13 provided that a normally closed relay contact 14 is in its closed position. The contact 14 is opened upon energization of a relay 15 which is connected to the battery through switches S1 to S5 in series. The switches S1 to S5 are spring loaded to the position shown, so that in use unless a switch S1 to S5 is operated, the relay 15 is energized and the contact 14 is open.

The system further includes a plurality of electrical loads L1 to L5 which are disposed in different parts of the vehicle and are connected to the supply line 12 through contacts C1 to C5 respectively. The contacts C1 to C5 are controlled by relays R1 to R5 connected through resistors 41 to 45 respectively to the line 13.

The arrangement as shown includes six feed lines 21 to 26, which together with the line 13 may be distributed in the vehicle in the form of a flexible printed circuit. The lines 21 to 26 are earthed through six resistors 31 to 36 as shown, and associated with the lines 21 to 26 are a plurality of pairs of diodes, the connections and purpose of which will become apparent on considering the operation of the circuit.

Assuming that the ignition switch (not shown) is closed, then power is supplied to the line 12, but none of the loads L1 to L5 is energized because the contacts C1 to C5 are opened. The relay 15 is energized, so that the contact 14 is open and no power is supplied to the line 13. 1f the driver wishes to energize the load Ll, he depresses the switch S1, immediately breaking the circuit to the relay 15 so that the contact 14 closes and power is supplied to the line 13. Current can flow from the line 13 through each resistor 41 to 45, and it will be seen that from the other end ofeach of these resistors there are three paths to earth, namely through the appropriate relay R1 to R5, and through the two diodes and associated resistors 31 to 36. The relay coil is energized only when all the current flowing through the resistors 41 to 45 flows through the relay coil, and so it will be seen that with the switch S1 closed, the lines 21,22 are connected to the positive terminal, so that the diodes connected to these lines cannot conduct. However, only the relay R1 has both its associated diodes non-conductive, and so only the relay R1 is energized.

All the relays R1 to R5 are of the kind which when energized with their contacts open cause the contacts to be closed, whereupon the contacts remain closed until the relay is de-energized and then energized again. Thus, upon depression of the switch S1 the contact C1 will close and the load Ll will be energized, and when the driver releases the contact S1, the relay 15 will be energized again, opening the contact 14, so that the relay R1 will be de-energized, but the contact C1 will remain closed. In order to de-energize the load Ll, the driver again depresses the switch S1, whereupon the same cycle of events takes place except that the contact C1 is now opened instead of closed.

It will be seen that operation of the switches S2 to S5 causes a different pair of supply lines 21 to 26 to be energized, and in each case the appropriate load L2 to L5 is energized. With the arrangement shown, fifteen loads could be controlled.

1 claim:

1. An electrical system for a road vehicle, comprising a battery having one terminal earthed, a supply line connected to the battery through a normally closed contact of a first relay, the coil of which is connected across the battery in series with a plurality of switches, the switches being associated respectively with a plurality of electrical loads on the vehicle and being arranged so that when any one switch is operated the first relay is de-energized, a plurality of feed lines, means whereby each switch when operated energizes a unique combination of at least two of the feed lines, a set of resistors connecting the feed lines respectively to earth, a first latching relay, the coil of which has one end earthed and its other end connected through a series resistor to the supply line, the first latching relay controlling a contact connected in series with one of the loads across the battery the junction of the first latching relay and its associated resistor being connected through control diodes respectively to the feed lines which are energized when said load is to be operated, further latching relays together with associated resistors and diodes being provided for the other loads,

and the arrangement being such that when a, switch is operated, the first relay is de-energized so that the supply line is coupled to the battery, current then flowing through each of the series resistors but then being stored between the associated latching relay and the series connection of control diodes and the appropriate resistor in the set of resistors, except in the case of the latching relay associated with the operated switch, where the appropriate control diodes are blocked and the latching relay is energized.

2. A road vehicle electrical system, comprising in combination with the battery of the vehicle an electrical supply line connected to said battery, a plurality of signal lines extending around the vehicle, a first load on the vehicle, a first switch on the vehicle and associated with said load, means whereby operation of said first switch energizes the signal lines in a unique combination whereby said unique combination is present on said signal lines only when said first switch is operated, a first control device connected to said signal lines, said first control device being energized by said unique combination and by no other combination of signals on said signal lines, means operable by said first control device when it is energized to connect said first load to said power supply line, a second load on the vehicle, a second switch associated with said load, means whereby operation of said second switch energizes a second unique combination of said signal lines, a second control device which is energized by said 

1. An electrical system for a road vehicle, comprising a battery having one terminal earthed, a supply line connected to the battery through a normally closed contact of a first relay, the coil of which is connected across the battery in series with a plurality of switches, the switches being associated respectively with a plurality of electrical loads on the vehicle and being arranged so that when any one switch is operated the first relay is de-energized, a plurality of feed lines, means whereby each switch when operated energizes a unique combination of at least two of the feed lines, a set of resistors connecting the feed lines respectively to earth, a first latching relay, the coil of which has one end earthed and its other end connected through a series resistor to the supply line, the first latching relay controlling a contact connected in series with one of the loads across the battery the junction of the first latching relay and its associated resistor being connected through control diodes respectively to the feed lines which are energized when said load is to be operated, further latching relays together with associated resistors and diodes being provided for the other loads, and the arrangement being such that when a switch is operated, the first relay is de-energized so that the supply line is coupled to the battery, current then flowing through each of the series resistors but then being stored between the associated latching relay and the series connection of control diodes and the appropriate resistor in the set of resistors, except in the case of the latching relay associated with the operated switch, where the appropriate control diodes are blocked and the latching relay is energized.
 2. A road vehicle electrical system, comprising in combination with the battery of the vehicle an electrical supply line connected to said battery, a plurality of signal lines extending around the vehicle, a first load on the vehicle, a first switch on the vehicle and associated with said load, means whereby operation of said first switch energizes the signal lines in a unique combination whereby said unique combination is present on said signal lines only when said first switch is operated, a first control device connected to said signal lines, said first control device being energized by said unique combination and by no other combination of signals on said signal lines, means operable by said first control device when it is energized to connect said first load to said power supply line, a second load on the vehicle, a second switch associated with said load, means whereby operation of said second switch energizes a second unique combination of said signal lines, a second control device which is energized by said second unique combination of signal lines, and means whereby energization of said second control deviCe couples said second load to said power supply line. 